Use of adsorbents for the purification of dry cleaning solvents

Abstract

The present invention refers to the use of an adsorbent comprising particles comprising an amorphous phase and a crystalline phase for the purification of dry cleaning solvents. The present invention furthermore relates to a filter unit containing such an adsorbent. It also refers to a dry cleaner containing a filter according to the invention. Additionally, the present invention refers to a process for dry cleaning textiles, wherein an adsorbent according to the invention is used.

1. A method for the purification of dry cleaning solvents, comprising use of an adsorbent comprising particles comprising an amorphous silica phase and a smectite phase, wherein the ratio of smectite phase/amorphous phase is within a range of 2 to 0.5. 
     
     
       2. A method according to  claim 1 , wherein the smectite phase represents a montmorillonite phase. 
     
     
       3. A method according to  claim 1 , wherein the adsorbent is used in the form of powders, agglomerates or granules. 
     
     
       4. A method according to  claim 1 , wherein the adsorbent is used as a powder with a particle size between 1 and 1000 μm, or as agglomerates or granules with a particle size between 0.01 and 10 mm. 
     
     
       5. A method according to  claim 1 , wherein the adsorbent is used in a suspended state or in an immobilized state. 
     
     
       6. A method according to  claim 1 , wherein the dry cleaning solvents are selected from the group consisting of perchloroethylene (PERC), hydrocarbons, silicones, and mixtures thereof. 
     
     
       7. A method according to  claim 1 , wherein the purification of the dry cleaning solvents comprises removing of impurities selected from the group consisting of non-volatile residues, lint, dyes, grease, soils, soaps, and traces of detergents. 
     
     
       8. Filter unit containing an adsorbent as defined in  claim 1 . 
     
     
       9. Filter unit according to  claim 8 , wherein the filter unit is a filter cartridge, of a carbon tower filter. 
     
     
       10. Dry cleaner containing a filter unit as defined in  claim 8 . 
     
     
       11. Process for dry cleaning textiles, wherein the textiles are washed using at least one dry cleaning solvent, and wherein the dry cleaning solvent/s is/are purified using at least the adsorbent as defined in  claim 1 . 
     
     
       12. Process according to  claim 11 , wherein the adsorbent is suspended in the dry cleaning solvent/s during the purification of the dry cleaning solvent/s, and wherein the adsorbent is separated from the dry cleaning solvent/s using a filter, in particular a nylon disc filter or a filter cartridge. 
     
     
       13. A process for dry cleaning textiles, wherein the textiles are washed using at least one dry cleaning solvent, and wherein the dry cleaning solvent/s is/are purified using a filter unit according to  claims 8 .